This application claims priority under 35 U.S.C. xc2xa7119 to German application number 102 10 174.4, filed Mar. 7, 2002, the entire contents of which are incorporated by reference herein.
The present invention relates to the field of technology of thermal turbomachines. It concerns in particular a thermal turbomachine according to the preamble of claim 1.
Such a machine and its exit-side rotor support in particular are known from publication EP-A1-0 491 966, the entire contents of which are incorporated by reference herein.
The bearing support of an axial flow gas turbine is described and shown in the aforementioned publication. In this gas turbine, an exhaust casing adjoins its exit-side rotor blades, the boundary walls of the exhaust casing being primarily made up of an annular inner part on the hub side and an annular outer part concentrically surrounding the annular inner part. The boundary walls delimit and form a diffuser. The exit-side bearing support of the rotor of the gas turbine is situated in the cavity of the inner part, the bearing support including a bearing accommodated in a bearing housing. In order to make the support of the exit-side bearing support independent of the influences of thermal load and thermal expansion of the housing and the diffuser walls, the position of the bearing housing may be adjusted using adjusting elements situated on the inner part of the exhaust casing and supported via at least one spring support on the foundation of the machine. The spring support includes one bar, which leads out of the hot diffuser area to the foundation.
A disadvantage in this known arrangement is that the vertical support of the exit-side bearing support is far too elastic for a bearing support of a turbomachine.
It is therefore the objective of the invention to devise a turbomachine having an exhaust gas-side bearing support, which has significantly increased stiffness compared to the known bearing support without giving up the advantages attained through the spring support.
This objective is realized with the entirety of features of claim 1. The core concept of the invention is to provide a spring-loaded bolted connection which restores a stiff connection with the bearing star (due to the pressure of the bolt springs).
A first embodiment of the turbomachine according to the invention, which is preferred in particular owing to its simplicity, is characterized in that the bearing saddle in a horizontal dividing plane is a separable part of a bearing star situated in the inner part of the exhaust casing and that the spring-loaded bolted connection is situated in the dividing plane.
Particularly advantageous circumstances result for the bearing support of the present invention if the spring-loaded bolted connection includes bolt springs, which in aggregate are designed for a force of the same order of magnitude as the spring supports.
In order to reliably avoid moment loads in an incident of unbalance, it is advantageous if according to another embodiment of the invention, the junction points of the bearing star with the inner part of the exhaust casing are positioned symmetrical to the bearing center.